Battery packs are used in many environments including medical equipment, environmental monitoring equipment and power tools, to name a few. Each battery pack can include, for example, one or more battery cells, connectors that are welded to the cells to electrically connect the cells, one or more sheets of vulcanized paper adhered to a top and/or bottom of the cells, and shrink wrap that encloses the cells, connectors and vulcanized paper.
The vulcanized paper, which is also known as “fish paper”, can serve to serve to insulate the cells and otherwise protect the cells from damage, such as damage that may result from an impact to the battery pack. Vulcanized paper can be adhered to the top or bottom of the cells in various manners. In one example, a worker can bond vulcanized paper to the cells by applying a layer of adhesive to the vulcanized paper and then quickly pressing the vulcanized paper against the cells and allowing the adhesive to set. In another example, the vulcanized paper can be manufactured to include an adhesive layer on one of its sides, and the adhesive layer can be covered with backing paper to protect the adhesive layer until the vulcanized paper is ready to be applied to the cells. At the time of applying the vulcanized paper to the cells, a worker can peel the backing paper from the vulcanized paper and then press the vulcanized paper against the cells to bond the vulcanized paper to the cells.
Bonding vulcanized paper to battery cells is problematic. Having a worker bond vulcanized paper to the cells by applying a layer of adhesive to the vulcanized paper and then quickly pressing the vulcanized paper against the cells and allowing the adhesive to set is an inefficient and time consuming operation. For example, the worker must manually apply the layer of adhesive to each piece of vulcanized paper and evenly distribute the adhesive on a surface of the vulcanized paper before bonding the vulcanized paper to the cells. Additionally, manufacturing vulcanized paper to include an adhesive layer on one of its sides and covering the adhesive layer with backing paper until the vulcanized paper is ready to be applied to the cells is also inefficient. Workers often struggle to remove the backing paper from the vulcanized paper. Since different patterns of vulcanized paper are often cut from stock sheets of adhesive-backed vulcanized paper using an automated die, laser or water cutting tool, it is impractical to use backing paper that is pre-scored (i.e., scored prior to cutting patterns into the stock sheet) because the scores may not line up with the cut patterns of vulcanized paper.